Fujitsu SPARC64 V Manual Do Utilizador
Release 1.0, 1 July 2002
F. Chapter L
Address Space Identifiers
123
BSTW Control Register (
ASI_C_BSTW0
,
ASI_C_BSTW1
)
The
BSTW
control register designates which bit in
LBSY
is written through
ASI_BSTW
x.
BSTW Busy Status Register (
ASI_C_BSTWBUSY
)
The
BSTW
busy status register indicates an update is made to
LBSY
in the SB and has
not completed yet.
Programming Note –
Supervisor software should not write to
ASI_C_BSTW
x
while
ASI_C_BSTWBUSY.BUSY
= 1. Otherwise, subsequent writes are ignored or a
write to wrong BST is sent to the SB.
[1]
Register Name:
ASI_C_BSTW0
,
ASI_C_BSTW1
[2]
ASI:
6F
16
[3]
VA:
80
16
(
ASI_C_BSTW0
),
88
16
(
ASI_C_BSTW1
).
[4]
RW
Supervisor read/write
Bit
Name
RW
Description
63
V
RW
Valid. When
V
= 0,
BL_num
and
SB_BPU_num
are
ignored and a write to
ASI_BSTW
x is discarded. When
V
= 1, data in the
ASI_BSTW
x is written to the selected
bit in
SB_BPU
.
6
SB_BPU_num
RW
SB BPU number on the SB.
5:0
BST_num
RW
BST
bit number in the selected SB BPU.
[1]
Register Name:
ASI_C_LBSTWBUSY
[2]
ASI:
6F
16
[3]
VA:
C0
16
[4]
RW
Supervisor read
Bit
Name
RW Description
0
BUSY
R
BUSY
= 1 is indicated when a write to
ASI_C_BSTWx
is made
but
LBSY
on the SB has not yet been updated.